PM / Wakeirq: Add automated device wake IRQ handling

Turns out we can automate the handling for the device_may_wakeup()
quite a bit by using the kernel wakeup source list as suggested
by Rafael J. Wysocki <rjw@rjwysocki.net>.

And as some hardware has separate dedicated wake-up interrupt
in addition to the IO interrupt, we can automate the handling by
adding a generic threaded interrupt handler that just calls the
device PM runtime to wake up the device.

This allows dropping code from device drivers as we currently
are doing it in multiple ways, and often wrong.

For most drivers, we should be able to drop the following
boilerplate code from runtime_suspend and runtime_resume
functions:

	...
	device_init_wakeup(dev, true);
	...
	if (device_may_wakeup(dev))
		enable_irq_wake(irq);
	...
	if (device_may_wakeup(dev))
		disable_irq_wake(irq);
	...
	device_init_wakeup(dev, false);
	...

We can replace it with just the following init and exit
time code:

	...
	device_init_wakeup(dev, true);
	dev_pm_set_wake_irq(dev, irq);
	...
	dev_pm_clear_wake_irq(dev);
	device_init_wakeup(dev, false);
	...

And for hardware with dedicated wake-up interrupts:

	...
	device_init_wakeup(dev, true);
	dev_pm_set_dedicated_wake_irq(dev, irq);
	...
	dev_pm_clear_wake_irq(dev);
	device_init_wakeup(dev, false);
	...

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h
index a0f7080..a344793 100644
--- a/include/linux/pm_wakeup.h
+++ b/include/linux/pm_wakeup.h
@@ -28,9 +28,17 @@
 
 #include <linux/types.h>
 
+struct wake_irq;
+
 /**
  * struct wakeup_source - Representation of wakeup sources
  *
+ * @name: Name of the wakeup source
+ * @entry: Wakeup source list entry
+ * @lock: Wakeup source lock
+ * @wakeirq: Optional device specific wakeirq
+ * @timer: Wakeup timer list
+ * @timer_expires: Wakeup timer expiration
  * @total_time: Total time this wakeup source has been active.
  * @max_time: Maximum time this wakeup source has been continuously active.
  * @last_time: Monotonic clock when the wakeup source's was touched last time.
@@ -47,6 +55,7 @@ struct wakeup_source {
 	const char 		*name;
 	struct list_head	entry;
 	spinlock_t		lock;
+	struct wake_irq		*wakeirq;
 	struct timer_list	timer;
 	unsigned long		timer_expires;
 	ktime_t total_time;